JP 2009-515090T discloses a technique related to the valve opening and closing timing control device.
The valve opening and closing timing control device includes a shaft portion in which a bolt that is inserted into the driven-side rotating body engages with the driven-side rotating body and the cam shaft coaxially with a rotational axis and a male screw section which engages with the cam shaft to fix the driven-side rotating body to the cam shaft.
The driving-side rotating body includes a sprocket around which an endless rotating body interlocked with a driving shaft of the internal combustion engine is wound. When the endless rotating body is rotated, the driving-side rotating body is pulled toward a driving shaft by driving the sprocket.
On the other hand, the driven-side rotating body is supported by an inside of the driving-side rotating body to be rotatable coaxially with the same rotational axis. Thus, if the driving-side rotating body is pulled toward the driving shaft, the driven-side rotating body is also pulled toward the driving shaft. The driven-side rotating body is fixed to the cam shaft by a bolt. Thus, if the driven-side rotating body is pulled toward the driving shaft, a bending force acts on the bolt.
The valve opening and closing timing control device of the related art is provided with an annular gap between an outer peripheral surface of the bolt and an inner peripheral surface of the cam shaft over an entirety of a region between the sprocket and the male screw section in a direction of the rotational axis. For example, the annular gap configures an annular flow path for supplying and discharging hydraulic fluid with respect to a fluid pressure chamber.
Thus, when the driven-side rotating body is pulled toward the driving shaft, in a region between the sprocket and the male screw section in the direction of the rotational axis, rigidity obtained in the bolt and the cam shaft is not sufficient and a deformation amount of the bolt and the cam shaft increases.
As a result, there is a concern that smooth rotation of the driving-side rotating body and the driven-side rotating body is deteriorated.